(PARI)
permcount(v) = {my(m=1, s=0, k=0, t); for(i=1, #v, t=v[i]; k=if(i>1&&t==v[i-1], k+1, 1); m*=t*k; s+=t); s!/m}
T(n, k)={my(s=0); forpart(p=n*k, s+=permcount(p)*polcoef(prod(i=1, #p, 1 + x^p[i] + O(x*x^n)), n)^k); s/(n*k)!} \\ Andrew Howroyd, Dec 10 2018